Antioxidant



Patented Jan. 30, 1945 2,383,435 ANTIOXIDANT Percy A. Wells, Abington,

schneider, Glenside, It. Wickard, as Secre United States in oihce and Roy W. Riemem' Pa., assignors to Claude tary of Agriculture ofthe of America and his successors No Drawing. Application January 13, 1943, Serial No. 412,280

12 Claims. (Cl. 26li-'398.'5) (Granted under the act of March 3, 1883, as

amended April 30, 1928:

This application is made under the act of March 3, 1883, as amended by the act of April 30. 1928, and the invention herein described, it patented, may be manufactured and used by or forthe Government of the United States of America for governmental purposes without the payment to us of any royalty thereon.

Our invention relates to antioxidants, and one of its objects is the provision of oxidative rancidity inhibitors for oleaginous materials of the lyceride type and other esters of fat acids.

It is common practice to incorporate various antioxidants and preservative agents with fats and oils to inhibit oxidative rancidity, the bjectionable odor and flavor imparted to the fats and oils as a result of oxidation by atmospheric oxygen.

It is known that ascorbic acid possesses rancidity-inhibiting properties, and it has been proposed to utilize ascorbic acid as well as its isomers and analogues as antioxidants in aqueous oil emulsion.

Ascorbic acid and other compounds of the ascorbic acid serie are, however, substantially insoluble in anhydrous fatty and oily substances, and this property limits their utility'as rancidity inhibitors.

We have found that the monoesters obtainedfrom reacting a saturated aliphatic monocarboxylic acid containing from 12 to 18 carbon atoms per molecule with compounds of the ascorbic acid series having the general formula,

(( JHOH),

mon where :c is 0 or a whole number not exceeding 3, are fat soluble substances having excellent ran cidity-inhibiting properties. The monoesters can be produced by reacting a compound of the ascorbic acid series with the corresponding aliphatic monocarboxylic acid asdescribed in the tion with water followed by solvent extraction. The method of preparing these monoesters is further illustrated by the following examples:

Example I ester of l-ascorbic acid, is prepared by dissolving 8.8 grams of l-ascorbic acid and 10.3 grams of palmitic acid in 100 cc. of percent sulfuric acid at essentially room. temperature. The solution is allowed to stand for about 16 hours after which the reaction mixture is poured slowly and with vigorous stirring into about 500 grams of chopped ice. The stirring is continued until the 8.8 grams of d-isoascorbic acid are esterifled with 10.3 grams of palmitic acid in cc. of 95 percent sulfuric acid by the procedure described in Example I. The reaction product after removal of unreacted palmitic acid consists essentially of d-isoascorbyl monopalmitate. The yield is good.

We have also found that certain of these substances, such as the ascorbyl and isoascorbyl monoesters, that is, the monoesters obtained by *using in the reaction compounds of the ascorbic acid series having the structural formulas,

II .LU

HO--OH Ascorbic acid and HaOH Isoascorbic acid l-ascorbyl palmitate, the palmitic acid monoare antioxidants especially edible fats and oils.

Thiguso is illustrated by the test procedures and tabulated results set forth below.

A number of 20 cc. samples of fatty materials containing varying amounts or the esters diswell suited for use in solved therein were placed m 50 cc w glass beakers, covered with watch glasses and kept in an oven, the temperature of which was maintained at 100 C. (:0.5 C.) by means of a thermostatically controlled heating device. At regular intervals the samples were examined for rancid odor. These organoleptic examinations content, using the well-known method based upon determination or free iodine liberated from potassium iodide by the peroxide-like oxidation products formed in the fatty materialss Thus, for lard the rancid odor became detectable when the peroxide content reached a value of :10 miili-mols mini-equivalents) per kilogram of fat; for alkali refined peanut oil the odor was noticeable at milli-mols; for alkali refined cottonseed oil at milli-mols, and so on.

The results obtained are shown by the tabupalmitate. No diiferences in taste or texture of the two lots of biscuits were observed. Stability tests on the dry, finely crumbled biscuits were carried out by using the oven test at C. After thirteen and one-half days the control biscuit was rancid while the biscuit containing the antioxidant had only a' stale odor. The fat extracted from the control biscuit had a peroxide value of for .rancidity were checked by tests for peroxide lation which follows. The stability of the tested.

materials as given in the table is the length of time the fatty materials remained under the above-indicated conditions before the atmospheric oxidation proceeded far enough to impart a detectable rancid odor to the material.

Substrate I Preserving agent used shortenings, the invention is applicable to the To determine whether lard containing monoester of compounds of the ascorbic acid series is satisfactory for baking purposes, biscuits were prepared by a standard recipe in which the shortening consisted of lard containing 1.0 percent of l-ascorbyl palmitate. For comparison, biscuits were made in an identical manner using Concentration of the yin stabilization of any oleaginous material comprising 'glycerides or other esters of fat acids.

Having thus described our invention, we claim:

1. The method of inhibiting animal and vegetable fats and oils against oxidative rancidity comprising incorporating therewith a monoester of a fatty acid containing from 12 to 18 carbon atoms per molecule and a compound of the ascorbic acid series.

Stability in hours oxidant oflect in agg-o 888 sscsassae'scsssa EEKWG 999999 999999 999999 99999999999999. crease gggs basaiassfise sesfiss 2. The method of inhibiting animal and vegetable fats and oils against oxidative rancidity comprising incorporating therewith a monoester of a saturated aliphatic monocarboxylic acid containing from 12 to 18 carbon atoms per molecule and a compound of the ascorbic acid series.

3. The method of inhibiting animal and ros the same lard without the addition or l-ascorbyl table fats and oils against oxidative rancidi y -rancidity development a monoester of a fatty acid containing 12 to 18 carbon atoms per molecule and a-compound of the ascorbic acid series.

6. An oleaginous composition comprising'animal and vegetable fats and oils having incorporated therein in an amount suflicient toinhibit rancidity development a monoester of a saturated aliphatic monocarboxylic acid containing from 12 to 18 carbon atoms per molecule and a compound of the ascorbic acid series. v

'7. An oleaginous composition comprising animal and vegetable fats and oils having incorporated therein in an amount suflicient to inhibit rancidity development an ascorbyl monoester of a saturated aliphatic monocarboxylic acid con- I taming from 12 to 18 carbon atoms per molecule.

8. An oleaginous composition comprising animal and vegetable fats and oils. having incorporated therein in an amount-suflicient to inhibit rancidity development an isoascorbyl monoester of a saturated aliphatic monocarboxylic acid containing 12 to 18 carbon atoms per molecule.

9. The method of. inhibiting animal and vegetable fats and oils against oxidative rancidity comprising incorporating therewith a monoester of a fatty acid containing from 12 to 18 carbon atoms per molecule and a compound having the formula Fif Hi J where a: is 0 or a whole number not exceeding 3.

10. The method of inhibiting animal and vegetable fats and oils against oxidative rancidi y comprising incorporating therewith a monoester of a saturated aliphatic monocarboxylic acid containing from 12 to 18 carbon atoms per molecule and a compound having the formula at 33311 ((JHOID:

H OH

where a: is 0 or a whole number not exceeding 3.

11. An oleasinous composition comprising animal and vegetable fats and oils having incorporated therein in an amount suflicient to'inhibit rancidity development a monoester of a fatty acid containing 12 to 18 carbon atoms per molecule and a compound having the formula L] HOE):

CHzOH where a: is 0 or a. whole number not exceeding 3.

12. An oleaginous composition comprising animal and vegetable ,fats and oils having incorpo-- rated therein in an amount suflicient to inhibit rancidity development a monoester of a saturated monocarboxylic acid containing 12 to 18 carbon atoms per molecule and a compound having a formula 00 (L-QH t i-on a J utnon).

HaOE

where a: is 0 or a. whole number not exceeding 3. PERCY A. WELLS. ROY W. RJEMENSCHNEDDER. 

